<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>注册页面</title>

    <style>
        .page-container {
            height: 300px;
            display: flex;
            justify-content: center;
            align-items: center;

        }
        .form-container {
            flex-grow: 1;
        }
        .form-group {
            margin-bottom: 1.5rem;
        }

        label {
            display: block;
            margin-bottom: .5rem;
            font-weight: 500;
            color: #333;
        }

        #phone {
            width: 100%;
            padding: .8rem;
            border: 1px solid #ddd;
            border-radius: 4px;
            font-size: 1rem;
            box-sizing: border-box;
            transition: border-color .3s, box-shadow .3s;
        }

        #phone:invalid {
            border-color: #ff4444;
            box-shadow:  0 0 2px rgba(255, 68, 68, 0.2);
        }

        #phone:focus {
            outline: none;
            border-color:#2196F3;
            box-shadow:  0 0 2px rgba(33, 150, 243, 0.2);
        }

        /* 提交按钮样式 */
        button {
            width: 100%;
            padding: 0.8rem;
            border: none;
            border-radius: 4px;
            background-color: #2196F3;
            color: white;
            font-size: 1rem;
            cursor: pointer;
            transition: background-color 0.3s;
        }

        button:hover {
            background-color: #1976D2;
        }

        .form-container {
            max-width: 400px;
            padding: 2rem;
            border: 1px solid #eee;
            border-radius: 8px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
        }


    </style>
</head>
<body>
    <div class="page-container">
        <div class="form-container">
            <form action="" method="get">

                <div class="form-group">
                    <label for="phone">手机号</label>
                    <input name="phone" 
                        type="tel"
                        id="phone"
                        required
                        pattern="^1[3-9]\d{9}$"
                        autocomplete="off" autofocus 
                        title="请输入正确的手机号"
                        placeholder="请输入手机号">
                </div>

                <button type="submit">注册</button>
            </form>
        </div>
    </div>
</body>
</html>